Liquid Fuel Combustion Using Porous Inert Media
Abstract
Combustion using porous inert media (PIM) offers benefits such as high power density, stable operation over a wider turndown ratio, homogeneous product gases, lower combustion noise and reduced emissions of NOx, CO, particulates, etc. Much of the previous research using PIM has focused on combustion of gaseous fuels, whereby the reactants are preheated by upstream transfer of heat from the flame region. In case of the flame stabilized within the PIM, the heat transfer is dominated by radiation and conduction from the reaction zone. The focus of the present study is to achieve lean premixed combustion (LPM) of liquid fuels using PIM. In particular, we seek to recirculate energy released in the reaction zone to pre-vaporize the liquid fuel and preheat the fuel-air mixture upstream of the combustor. Further, a PIM section is used upstream of the combustor section to promote fuel-air mixing and hence, to achieve uniform combustion without the fuel-rich or fuel-lean regions that tend to increase the emissions of particulates, CO, NOx, and UHCs. Two test facilities were developed in this project: (i) a non-reacting set up with controlled heat input to the PIM to simulate upstream heat transfer, and (ii) a combustor set up capable of providing emissions data over a range of operating conditions. The experiments are complemented with computational fluid dynamic analysis to model the fuel vaporization, fuel-air premixing and reactant preheating. Combustion experiments were conducted using a commercially available injector and a custom designed two-fluid atomizer. Results show that a finite fuel-air premixing region upstream of the PIM section is necessary for complete mixing, and hence, to achieve low-emissions with liquid fuel combustion. The length of the premixing section can be reduced significantly through injector design.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2006
- Accession Number
- ADP023642
Entities
People
- Ajay K. Agrawal
- Subramanayam R. Gollahalli
Organizations
- University of Alabama